Method of cooling gases.



No. 650,608. Patented May 29, I900. T. J. McTlGHE.

METHOD OF COOLING GASES.

(Application filed Aug. 30, 1899.)

(No Model.)

wuwniioz glass fall-tube exhibiting an alternation of UNITED STArns PATENT Series.

'iliOixiAS J. MC'IIGHE, OF NEW YORK, N. Y.

METHOD OF COOLiNG GASES.

SPECIFICATION forming part or Letters Eatent No. 650,608, dated May 29, 1900.

Application filed August 30, 1899. Serial N 728,979. (No specimens.) 7

T0 a-ZZ whom it may concern.-

Be it known that I, THOMAS J. MCTIGHE, a citizen of the United States, and a resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Methods of Cooling Gases, of which the following is a speci: fication.

This invention has for its object the cool ing of gases either for the production of a refri geratin g eifect or for the liquefaction of gas.

The invention consists, briefly, in causing a compressed gas to act expansively in elevating within a heat-insulated tube a suitable liquid cooler than itself, thereby doing work and falling in temperature in proportion to the work done. f

The invention further consists in utilizing the energy of position thus attained by the liquid by causing it to descend by gravity and actuate a suitable motor which is geared to mechanism for performance of work.

The invention further consists in the various processes and combinations of steps, all substantially as hereinafter fully described, and set forth in the claims.

It 'is well known, as illustrated by the familiar Sprengel or Geissler pump for exhausting lamp-bulbs and other apparatus, that a falling column of mercury or other liquid causes the withdrawal of portions of air from the bulb 01' apparatus, the dropping of the mercury continuously drawing air and the mercury and air, each being separated from the other in more or less regular sections and each filling the diameter of the tube. I reverse these relations, and instead of a series of moving bodies of liquid-pulling with them a like series of bodies of gas I place the gas under compression and cause it to expand and push upwardly a series of bod of any desired liquid. An important principle of thermodynamics .is thus brought into play. It is known that a compressed gas when allowed to expand through a small aperture loses some of its heat in the operation; but the reduction of temperature is very slight. On the other hand, it is also well known that ii a compressed gas be caused to expand and do. work while expanding, such as moving the piston of an engine, a very great reduction of temperature is obtainable, only limited by the mechanical difficulties of lubrication and escape of the chilled gas. Of these two methods of cooling a gas the latter is by far the more eificient, theoretically; but the formerhas been most generally adopted in liquefaction processes, owin g chiefly to the above difficulties, the absence of moving parts, and the resulting simplicity of apparatus; but by the adoption of my invention I am enabled to obtain the maximum thermodynamic efficiency of conversion of heat into work, the same as though I were expanding the gas against the piston of an engine, without being obliged to employ moving mechanism. I cause the compressed gas to enter the lower end of a tube submerged in a suitable liquid and push such liquid up the tube, the gas expanding continuously as it rises until it emerges at atmospheric pressure-that is to say, the gas has done mechanical work and by thus parting with energy has become lowered in temperature.

More particularly, my invention will be understood by reference to the accompanying drawing, which forms part of this specification, wherein the figure is a diagrammatic illustration, partly sectional, of an apparatus embodying the principles of my invention.

A is a stand-pipe surrounded by a suitable jacketing to prevent the undue passage of heat inwardly fromthe surrounding atmosphere. The stand-pipe A ends at its top in a separating-chamber B. From the latter two pipes (also heat-insulated) descend; .the pipe C from near the bottom of the chamber and the pipe D from near the top of the chamber.

The stand-pipe A terminates below in a reservoirE and is preferably bell-mouthed, as shown. The liquid-pipe O has connected into it near its.lower end a suitable hydraulic motor F-suoh, for example, as a tu rbine whee the discharge-pipe from which enters the res ervoir E. The shaft of such motor may be geared to any sort of work-absorber; but I from chamber B and conducts it downto the intercooler II, after flowing through which the expanded gas passes over by the pipe I to the compressor to be again compressed.

From the compressor the gas passes by pipe k to andthrough the cooler L and from it by proper quantity of liquid at a low temperature, the compressor is set going. The heat of compression is first absorbed by the ordinary cooler L, which contains water or other suitable cooling agent. Thence the cooled gas passes on under pressure to the nozzle n, from which it rises in a continuous succession of bubbles, into and up the pipe I A. Each bubble of gas pushes ahead of it a portion of the liquid which is in the reservoir, and, as in the Sprengel air-pump, the two retain their separate character, each filling the diameter of the pipe A. Each section orbubble of gas,

- however, begins at once to exertits expansive power and expands more and more as it pushes the body of liquid ahead of it up the pipe-A until with due proportioning of the height to the initial presence of the gas and the density ofthe liquid used-the latter is ejected from the pipe Ainto chamber B, and

the now more or less completely expanded gas follows it. This action is repeated by further quantities of gas and liquid in rapid succession. compression has been removed has now had I a large amount of its iutrinsicheat energy converted intowork, and it has fallen to a very low temperature. The-liqu id gravitates down the pipe 0, and by means of the motor F the gravitational energy of the liquid passes off in the form of work externally instead of becoming converted into heat andv is discharged into the reservoir at its normal temperature to be again elevated and made the means of conversion of heat into work. cooled gas passes from the chamber B down the pipe D and through the intercooler H, where by contact with the pipe m it absorbs heat from the compressed gas coming from the compressor, lowering the temperature of such gas, and this now entering the standpipe at a temperature lower than in the preceding cycle sufiers a greater fall of tem perature by its expansion in pipe A.

For more refrigerating or ice-making purposes it is sufiicient to pass compressed air once through the above cycle and utilize the chilled air directly from chamber B without using the intercooler '11.. For liquefaction purposes, however, I propose to prime the apparatuswith the liquefied gas and repeat the cycle continuously.

rapidly effected, since not only is there a The chillingis thus very self-intensive elfect produced in succeeding cycles by the gas coming from chamber I) be- The gas from which the heat of mechanical work The ing used, over after passing-the intercooler, but there is a direct cooling due to the contact of the gas with its own liquid form in the stand-pipe and a further cooling eifect due to the evaporation on the surfaces of the liquid. The action is so rapid and reduction of temperature so great that a gas can be liquelied very copiously. The surplus gathers in the reservoir E, whence it can-be drawn olf by the faucet p. To make up for the gas thus liquefied, more gas can be supplied at the filtering-funnel s as needed.

If air be under treatment, the action of the funnel s is automatic, since the spent air in pipe 11 is approximately down to atmospheric pressure and the compressor will draw in at 8 what is wanting in pipe '8.

For refrigeration of air for ice-mak'in g purposes, &c., the priming liquid can be a mixture of salt and water or glycerin and water or other mixture, so that the gas-may, if desired, be carried down to a-temper. ture much below 32Fahrenheit.

Having described my invention, 1. claim- 1., Tlie method of cool'ng a gas, consisting in compressing the. gas, removing the heat of compression, and then causing the gas to become lowered in temperature by expanding directly againsta counter-resisting liquid pis ton, and using such expanded and cooled gas to cool a further body of compressed gas, and then causing the latter to pass through the same cycle of operation. v

2. The method of cooling a gas, consisting in compressing the gas, removing the heat of compression, and then causing the gas to do against a piston consisting of the same gas liquefied, while insulating the said gas and liquid against external heat.

by expanding directly 3. In the process of cooling a gas by causin g it under pressure to do work expansi'vely in lifting acolumn of liquid and allowing the elevated liquid to gravitate to its original level for continued use,'themetliod of preventing such descent from generating heat, consisting in causing the gravitational energy of the liquid to pass oit in the form of external work instead of becoming converted into heat. a

4. The method of liquefying gas, consisting in compressing and cooling the gas, then causing it to do mechanical work by expanding directly againsta piston of. liquid and clevating the same until expansion has taken place, returning the expandedlgas for further compression while utilizing it to cool a further quantity of compressed and cooled gas prior to expansion of the latter, and continuing such cycle of peration till liquefaction of the gas ensues.

5. The method of uquefyin g gas,wh1ch consists in compressing and cooling the gas, then causing it to expand against and in contact with a vertical column of vapo'rizable liquid. then separating the gas and liquid, returning-f the cooled-gas to the com pressorand ut ilizing it in its return to absorb heat from the nonto gravitate to its original level and in its de-- expanded compressed gas, causing the liquid scent to do mechanical work, repeating the above cycle and-supplying new gas to the compressor according to the demands of the 6. ,The method of liquefying air, consisting in compressing and cooling the air, then 10wering its temperature farther by conduction in a suitable counter-current.apparatus,';and'

then causing the compressed and supercooled airto-do mechanical work by expanding di- 'rectly against a piston-of liquid air,

7. The method of liquefying air consisting 15 Columbia, this 29th day ofAugust, A. D. 1899. 20 r THOMASJ. McTIGHE. .Witnesses:

ANTHONY 'N. CONNOLLY, Jos. B. CONNOLLY. 

